(1) Field of the Invention
This invention relates to alarm and warning systems, but more specifically, it relates to apparatus for assuring the reliability of visual fire alarm and warning systems for buildings and institutions frequented by persons having impaired hearing ability.
(2) Description of Related Art
Visual alarm systems have been used to alert persons having impaired hearing capabilities, the alarm being given by the flashing of a lamp installed within a room or area occupied by such persons. In large institutional structures it is especially important that equipment and methods be provided to test the alarm circuits and components to assure their reliability without causing undue concern by hearing impaired occupants who may interpret a test as an authentic emergency.
Zinsmeister (U.S. Pat. No. 3,810,170) discloses a visual signaling system for deaf persons using a high intensity strobe lamp. Means for testing and assuring the reliability of the apparatus are not provided.
Pichey (U.S. Pat. No. 4,017,825) teaches a highway intersection warning system for alerting motorists to the proximity of emergency vehicles and suggests but does not develop circuitry for a strobe lamp. The disclosure does not teach a means for testing and assuring the reliability of the warning system.
Finnegan (U.S. Pat. No. 4,222,047) teaches a failure detection apparatus for incandescent lamps using a low level test signal that does not illuminate the lamp in question. The apparatus is not applicable to the testing of high voltage discharge triggered lamps.
Johnson (U.S. Pat. No. 4,199,754) discloses a fire detection and emergency system, operable with an incandescent lamp fixture, with auxiliary lighting for fire and power failure conditions wherein circuitry is provided to bypass the on-off switch of the general illumination lamp. The apparatus does not operate with a flashing alarm lamp.
Mongoven (U.S. Pat. No. 4,449,073) discloses an airport runway approach lighting system including strobe lamps and discharge current monitoring means of fault detection.
Cady (U.S. Pat. No. 3,189,788) discloses a battery operated circuit for the illumination of indicating lamps upon failure of AC line power.
It is common practice to test fire alarm circuits by sending a current through the circuit and monitor the current flow to activate warning devices if a deficiency in current flow appears. But strobe lamps are especially useful for alerting hearing impaired persons to emergencies, however, the reliability of a strobe lamp cannot be tested or monitored by means of a low lever continuous current. In institutional buildings it is not practical to frequently flash test the full complement of all the strobe lamps at once, because, being understood to represent a fire alarm, such testing could frighten the hearing impaired occupants or cause them to take unwanted action.